Liquid cooling apparatus and installations

ABSTRACT

A large scale liquid cooling assembly includes a plurality of individual liquid cooling spray units arranged in parallel pairs of rows extending perpendicularly from a main liquid supply channel toward a cooled liquid receiving area. Each row of a pair includes at least two spray units, and the units in each such row of a pair are aligned and oriented to project liquid drops in trajectories which have horizontal components extending outwardly from that row and toward the opposite row of the same pair. The spray units at the ends of each such row further project such drops in trajectories which have horizontal components extending angularly in a direction toward the opposite ends of the opposite row of the pair. Thus, the projected liquid drops can provide wind effects which draw air inwardly from both ends of each pair of rows toward a central area between the opposite rows of such pair. The air reaching this central area has its temperature increased by transfer of heat from the liquid drops and is forced upwardly out of the area in a &#39;&#39;&#39;&#39;chimney&#39;&#39;&#39;&#39; effect. Improved liquid cooling assemblies particularly suitable for such installations, but which also have other applications, include a liquid projecting rotor member, and means supporting the rotor member for rotation on a generally horizontal axis. Such a rotor member has at least one and preferably a plurality of paddle-like blade portions each of which has a cross section which extends generally radially outwardly from the rotor axis and has an outer peripheral liquid projecting edge, in combination with liquid feeding means for feeding liquid inwardly from a location at the peripheral edge of the blade portion to the angular space swept by such blade portion during successive rotations of the rotor member around said axis. The liquid feeding means and rotor blade constructions are shown in various combinations and details.

United States Patent [1 1 Boler et al.

[4 1 Oct. 14, 1975 LIQUID COOLING APPARATUS AND INSTALLATIONS [75] Inventors: Leonard J. Boler, Minneapolis;

Bryan J. Beaulieu, Hopkins; Leander J. Stoesz; Mandel L. Desnick, both of St. Louis Park, all of Minn.

[73] Assignee: Cherne Industrial, Inc., Edina,

Minn.

22 Filed: Apr. 10,1973

21 Appl. No.: 349,782

[52] US. Cl. 261/90; 261/92; 239/220;

239/224 [51] Int. Cl. BOIF 5/22 [58] Field of Search 239/550, 219221,

[56] References Cited UNITED STATES PATENTS 721,445 2/1903 Holmstrom 239/224 1,667,291 4/1928 Lavett 239/220 1,848,202 3/1932 Scott.; 261/92 2,007,734 7/1935 Wergifosse 261/90 2,152,688 4/1939 Guenst 239/220 2,215,753 9/1940 Goodman et al. 261/92 2,528,566 1 H1950 Whisenhunt 239/220 2,934,325 4/1960 Haglund 261/92 3,658,305 4/1972 Newtson 261/92 3,703,462 11/1972 Smith 261/92 3,719,353 3/1973 Cheme et al. 261/92 FOREIGN PATENTS OR APPLICATIONS 383,680 l/l908 France 261/90 168,867 10/1922 United Kingdom.. 261/90 8,798 4/1908 France 261/90 Primary ExaminerTim R. Miles Attorney, Agent, or FirmDorsey, Marquart, Windhorst, West & Halladay 57 ABSTRACT A large scale liquid cooling assembly includes a plurality of individual liquid cooling spray units arranged in parallel pairs of rows extending perpendicularly from a main liquid supply channel toward a cooled liquid receiving area. Each row of a pair includes at least two spray units, and the units in each such row of a pair are aligned and oriented to project liquid drops in trajectories which have horizontal components extending outwardly from that row and toward the opposite row of the same pair. The spray units at the ends of each such row further project such drops in trajectories which have horizontal components extending angularly in a direction toward the opposite ends of the opposite row of the pair. Thus, the projected liquid drops can provide wind effects which draw air inwardly from both ends of each pair of rows toward a central area between the opposite rows of such pair. The air reaching this central area has its temperature increased by transfer of heat from the liquid drops and is forced upwardly out of the area in a chimney effect.

Improved liquid cooling assemblies particularly suitable for such installations, but which also have other applications, include a liquid projecting rotor member, and means supporting the rotor member for rotation on a generally horizontal axis. Such a rotor member has at least one and preferably a plurality of paddle-like blade portions each of which has a cross section which extends generally radially outwardly from the rotor axis and has an outer peripheral liquid projecting edge, in combination with liquid feeding means for feeding liquid inwardly from a location at P the peripheral edge of the blade portion to the angular space swept by such blade portion during successive rotations of the rotor member around said axis. The liquid feeding means and rotor blade constructions are shown in various combinations and details.

21 Claims, 11 Drawing Figures U.S. Patent Oct. 14, 1975 Sheet 1 on 3,912,797

XLL-

Sheet 3 of 3 US. Patent Oct; 14, 1975 .1 I LIQUIDCOOLING APPARATUS AND INSTALLATIONS BACKGROUND OF THE INVENTION There is a continuing need for improved apparatus and installations in which large quantities of water or other liquids can be cooled such liquid is often used for the cooling of apparatus in an operating plant, and the heated liquid which is delivered from the heat exchangers of such a plant, after performing the desired cooling function, must be cooled again to a substantial degree either for recirculation and further use within such plant, or for reintroduction of the liquid to a natural source, such as a lake or river, from which it may have been drawn initially. Many different devices, such as large cooling towers, cooling ponds extending over substantial areas of land, and various aerating devices, have been used or suggested for the cooling of desired quantities of liquid to avoid the problems generally referred to as thermal pollution or merely to provide desired cooling of such liquid for recirculation. Some earlier devices and installations, in which liquid is sprayed or aerated in some manner above a cooling pond or liquid reservoir, have been handicapped in operation under certain ambient conditions, for example, by saturation of the air above such an installation with moisture, and by a reduced cooling efficien'cy when certain ambient wind directions and wind velocities are involved.

SUMMARY OF THE PRESENT INVENTION The present invention accordingly provides an improved large scale liquid cooling installation which includes a plurality of individual liquid cooling spray units arranged in generally parallel pairs of rows, with at least two such units in each row, and with the spray units in each row of each pair aligned and oriented to project liquid drops in trajectories which have horizontal components extending outwardly from such row and toward the opposite row of that pair. The spray units at the ends of each such row project such drops angularly in trajectories which have horizontal compo nents extending in a direction inclined toward the opposite ends of the opposite row of that pair, with the projected liquid drops providing wind effects which draw air inwardly from both ends of each pair of rows toward a central area between the opposite rows of each pair. The preferred installation includes a plurality of liquid supply branch conduits extending generally parallel to each other and to said rows of spray units, with a supply branch conduit adjacent each: row of spray units in each of said pairs, said installation further including a main liquid supply conduit extending horizontally and generally perpendicular to said branch conduits along one end of the parallel rows, and with a liquid receiving reservoir extending generally perpendicular to said branch conduits along the opposite end of such parallel rows, with portions of such reservoir extending between the spray unit rows of each pair for receiving the liquid drops projectedby said spray units into the central area between the opposite rows of the pair.

The invention further provides improved liquid cool-. ing assemblies particularly suitable for use in such installations, but which also have other applications. Such assemblies include a liquidprojecting rotor member, with means supporting the rotor member for rotapaddle-like blade portions each of which has a cross section, as measured in a plane perpendicular to said axis, which extends generally radially outwardly from the axis to an outer peripheral liquid projecting edge, in combination with liquid feeding means for feeding liquid inwardly from a location at the peripheral edge of the blade portion to the angular space swept by the blade portion during successive rotations of the rotor member around its axis. In one form of rotor, each blade portion has axially spaced cross sections at the same relative radial angles, with such cross sections defining an axially extending blade portion having an outer edge extending generally parallel to said axis. In another form, the blade portion has axially spaced cross sections at successively progressing relative radial angles, with such axially spaced cross sections defining an axially and helically extending blade portion with its outer edge extending generally spirally around said axis. Such blade portions may extend continuously along a substantial axial length of the rotor member. Alternately, individual radially extending blade portions may be spaced axially from each other along the axis, with each blade portion positioned at a circumferential angle which locates that blade portion as a liquidprojecting surface which is substantially a continuation of the surface established by axially adjacent blade portions.

The invention also provides various combinations of liquid feed means, one of which includes an opentopped channel into which only the lower peripheral edges of the rotor blades. can project to feed some of the liquid on to the blades for. projection and cooling of liquid drops at a high "volume rate. In another form the feeding means includes a liquid supply conduit spaced below or at one side of such a rotor member and having a liquid delivery device to project the liquid from such conduit to the angular space swept by the rotor blades. One form otldeliyery device according to the invention projects the liquid vertically upwardly from a pressurized liquid supply conduit below the rotor member, by means of? upwardly directed nozzles having liquid delivery surfaces and discharge edges projecting the liquid vertically up toward the rotor member axis and into the angular space swept by the rotor blades. In another embodiment, the liquid supply conduit is an open-topped conduit having a side wall extending along one side of the rotor member for maintaining a level of liquid higher than the vertical location of the rotor axis, and the liquid delivery device includes a liquid delivery surface having a discharge edge at said one side of the rotor member immediately adjacent the path swept by the outer ed'gesa of the rotor blades. One liquid delivery device forsuch-an embodiment includes a manifold on the outer wall of the supply conduit with a plurality of horizontally and axially space nozzles each providing individual liquid delivery surfaces and discharge edges across which iiquid is projected with a horizontal component of movement into said angular space. In a preferred embodiment such a liquid delivery device includes an overflow edge along the top of the conduit side wall, and said liquid delivery surface is a downwardly sloping open-topped surface extending laterally toward the rotor member and having its discharge edge extending parallel to the rotor axis for projecting a sheet of liquid into such angular space in a direction having a horizontal componentof movement and, if desired, an upward-vertical component, whil'e said-rotoris" rotated around itsaxis in adir'ectiori moving e achblade" portion'upwardly past the discharge edge.

"'jIn some of the foregoing embodiments, the invention provides the outer edges-of the rotor blades with' sh ort outer. lip portion s inclined forwardly in the direction of rotation of the rotor blades to assist in feeding the liq- I uid onto the radialblade portions for projection of the desired drops. The-invention also provides a rotor constructioncapable of selective rotation in either direction around its-axisand. with short outer lip portions at the outer :edges of each rotor blade extendingin both directionsv ofzpossible rotation to assist in-feedingthe liquid on to-the'radial blade portions, which are unperforated, for:selectivezprojection' of liquid'drops in either direction of rotation. a

Additional features-and advantages of the invention will beapparent'from the following description, in which m preferred embodiments are-shown and de- 1 scribed'in greater detail "BRIEF DESCRIPTION oF THE DImwI os in the drawings form a part of this application, I which like' r'e ferencecharacters indicate like Parts,

FIG. 1 isa plan view of a portion of a preferred large scale liquid;cooliiig ,installation having a plurality ofliq- .uid; cooling sprayf uni ts arranged in parallel pairs of rows extendingperpendicually from a main supply con- I. FIG. 3-is a partial-sectional view-.on

,an enlarged plan view of one :pair of rows from theIinstall-a-tion of FIG. 1; I l I the' line; 33. of FIG'. 2,-' showingidetails ofa preferred liquid feeding de vice; I

FIG-:4 "is' a view similarto FIG. 3 of a modified form of liquid feeding device of the general type shown in idevice and installation 6 FIG. 5;

FIGIS; i

FIG] 5 is "a view'similar to FIGS. 3 and 4 of still another'fee ding device; I i

FIG 6 isaplan 'view showing'further details of the *1 FIG; 1 is partial elevational view of another emb odiment of a liquidcooling assembly unit, in which'axially spaced 'rotoif'blade portionsa're provided, and-in which a pressuriZe'd, liquid supply conduit is'located below the rotormernber axis toproject liquid upwardly .into the space swept the rotor blades;

FIG. is a partial sectional on the line 8 8 of FIG. 7; 1 J- FIGL 9. is a embodiment of the invention inwhich, the liqui d feeding meansincludesan open-topped liquid supplychanme] into which only. the lowermost edges of the rotor blades project; a

view similar to b 8 of another FIG. is a'plan view showing further details of the embodiment of FIG. 9 and FIG-I1 a a view similar to FIG. 9 of a modified de- "vicesimilar to that of FIGS. 9 and10 in'which the rotor "member is adapted for rotation "inieitherdirection for selective projection of liquid drops'toward either side of the liquid supply channel.

. 3, DEscRIP'IIoN oF FREFERRED I 1 1 EMBODIMENTS} As sho wn in FIG. 1, one liquid cooling installation according to the inventionincludesa special, arrangement of liquid projecting and cooling assemblies along at least one side ,ofa longitudinally extending channel 11 'for heated liquid. Channel 11 is definedby side walls 12 and 13, and a plurality of auxiliary or secondary channels 14, 16, 1'7, l7, l8 and 18' extend generally perpendicularly away from themain channel 11 atone sideofthat channel. Each of these branch or secondary channels supplies heated liquid to a plurality of projectingand cooling units which are located on one side of each channel as shown more fully. in the enlarged partialv view of FIG. 2. Thus auxiliary channel 16, for example, includes side wall portions. 19 and 21. Similarly member. 25 is .pivotally supported on the side wall 13 sothat it maybe moved on wall 13 tobloc k opening 24 and to be held against thev opening b y the pressure of liquid in channel 11. Thus secondary channel 16, or any of the other such channels, can be selectively cut offIso thatthey can 'be drained of liquid whenever it is necessary or desirable toprovide maintenance work or .repair or replacement in connection with the individual liquid projecting and cooling units associated "with that branch. The size of opening is chosen to accommodate only the'volume rate of flow needed to feed the rotor members served by that branch channel. Thus a higher liquid level can be maintained in main channel 1 1 than in the branchchannels such as 16, as shown in FIG. 3." Y l .A reservoir portion 26 for cooled liquid extends alongthe opposite ends of the branch channels and in- 1 cludes' liquid receiving areas27 and 27,, for example,

between the respective oppositerows of liquid spraying units, which are arrangedin a plurality of pairs of parallel rowszas in FIG. 2. FIGS. 1 and 2 showonly as mall portion of a large scale liquid cooling, installation. In

.one proposed layout, the main channel 11 can extend around oralong desired edges of a relatively large area, With a large number of pairs of oppositely directed par- .allel rows of spray units extending perpendicularly from main conduit 11 foras much as 140 feet or more toward a receiving reservoir portion such as 26. 1 According to the system layout of the present invention, the auxiliary branch 16 has two liquid projecting -=rotor,members- 28 and 29 at one side of the channel 16.

:These rotor or liquid projecting spraying members are supported'in bearings 31 811C132 for rotation around a .generally,' horizontal axis,- 'as .driven one or more powerfunits Powerunit '33 maybe an electn'c motor, or any other desired ular installation:

source of power for the partic- Asimilar row of axiallyaligned'spraying members 34 and :36 are positioned opposite members 28 and 29 on thefacing side-of -the riext auxiliarychannel 17. These liquid spraying members341 and 36 are supported by bearings 37 and 38 and driven by power units 39.

In order to achievethe desired wind effects according to the present invention, rotor members 28, 29, 34 and 36 are preferably constructedwith'spiral paddle- Iike blades. Thus each rotor has a series of spaced supporting plates 41 secured to a supporting shaft 42, with continuous or individual spiral paddle portions 43 and 44 positioned 180 apart around axis 42, as shown in further detail in FIG. 3.

Liquid is fed from the respective secondary channels to each of the individual spraying rotors in any desired manner. A preferred feeding arrangement is shown in FIG. 3, in which the secondary channel 16 has its side wall 21 cut away to provide an overflow edge at 46. Wall portion 21 also is provided with a downwardly sloping spillway portion 47 which is inclined relatively steeply from the overflow edge 46 to a lower area 48, at which the spillway levels off and terminates in a discharge edge 49 which extends longitudinally or axially parallel to the spraying rotor axis 42 at a point spaced just outwardly from the path of movement of the outer edges of blades 43 and 44. Spillway portions 47 and 48 provide a liquid delivery surface for rotor 29.

Thus a liquid sheet 51 can overflow from channel 16 at the edge 46 of the spillway, and this feeding arrangement then projects the sheet of liquid from the discharge edge 49 inwardly in a direction generally toward the axis 42, as indicated by arrow 52. The spillway extends axially the full length of the rotor member 29, and a similar spillway section is provided for each of the other rotors for supplying liquid uniformlyto them from their respective associated secondary channels.

The height and slope of the spillway portion 47 are designed to provide a sufficient pressure head to project the liquid from the discharge edge 49 with sufficient velocity to insure its penetration inwardly beyond the outer edges 53 of the individual rotor blade portions, and toward, but not beyond, the inner edges 54 of these blades, during the time interval between the passage of successive blade portions past the discharge edge 49. Thus, in the double bladed rotor construction shown, blade 44 will intercept that portion of the liquid which has been projected above it, and rotation of the rotor member in the direction of arrow 56 will, project drops of such liquid tangentially in the direction, for example, of arrow 57 in FIG. 3. The drops of liquid are thus projected upwardly and away from this side of the secondary channel 16 and generally crosswise toward the next adjacent secondary channel 17 (FIG. 2). The drops project in groups, with one group projected by each blade passage at edge 49.

Moreover, the particular arrangement of the spiral paddle blades projects the liquid in trajectories with a horizontal component which extends at an acute angle to the horizontal rotor axis or shaft 42. Thus, as shown in FIG. 2, the spiral blade portions 43 and 44 are arranged with a helical configuration or spiral in one direction, so that liquid projected perpendicularly from the surface of each blade will be projected at a horizontal angle as shown by arrow 61, which has components extending both horizontally across toward the other secondary channel 17, and also axially parallel to rotor shaft 42 and toward the other rotor member 28 at the other end of this same shaft. The second rotor member 28 has its spiral blades inclined along an opposite spiral or helix, so that the liquid projected perpendicularly from the surface of its blades is projected in a direction as shown by arrow 62, with part of its movement directed across toward the opposite secondary channel 17 and part of its movement directed axially toward the main channel 11 for heated liquid.

Similarly the opposite spray members 34 and 36 also have oppositely directed spiral blade arrangements, so that rotor member 36 projects its liquid drops in the direction of arrow 58, while rotor member 34 projects its drops in the direction of arrow 59. Thus all four of the rotor members 28, 29, 34 and 36 are arranged to project liquid generally toward a vortex 68 or central area roughly midway between the two secondary channels 16 and 17 and approximately halfway between the main hot water channel 11 and the outer edges of the secondary channels. I

This arrangement of parallel channels 16, 17 etc. for heated liquid and liquid projecting rotor. members which are designed and arranged to project drops of liquid angularly from each end of each parallel heated liquid channel toward the central area intermediate the ends of such channels and at a location-between each pair of channels is particularly advantageous in insuring adequate cooling of large volumes of liquid under wind conditions which for one reason or another are likely to adversely affect the evaporative cooling of the drops. For example, if the wind direction in the layout of FIGS. 1 and 2 is generally parallel to the individual heated liquid branch channels 14, l6, 17, etc., and if these channels are not too long, then the wind can effectively pick up heat from the projected drops as the wind passes along parallel-to the channels, and the wind can continue in that direction away from the channels while a fresh supply of cooler air is constantly received from the upwind side of the installation.

On the other hand, if the wind direction is perpendicular to the parallel channels 14, 16 etc. as shown by arrow 63 in FIGS. 1 and 2, and if there are a large number of these branch channels extending over quite a distance along the main heated liquid channel 1 1, then the fresh air which first encounters the first cross channel and its liquid cooling members will be effective for evaporative cooling of that liquid, but will tend to pick up enough heat so that it would ordinarily be difficult to provide a fresh air supply for the further branches and cooling units in a downwind direction. The particular angular arrangement "of liquid projection as shown in FIGS. 1 and 2, however, tends to draw fresh air inwardly from each end of the parallel branches, as shown by arrows 64 and 66, as. a result of the wind effect which can be generated by projecting liquid drops along desired horizontal components of direction in sufficient quantity and at a sufficient projection velocity. As these individual air currents are drawn inwardly and angularly toward the center of the space between adjacent parallel branches of the installation, they tend to provide an induced draft effect, so that the. heated air is driven upwardly at the central area 68 between each pair of branches, as shown by arrow 67 in FIG. 2.

The tendency of heated air to rise, and the projection of liquid drops in directions which draw additional supplies of cool air in at each end of each pair of rows thus make it possible to more effectively cool large quantities of liquid by evaporative cooling, as drops of such liquid are projected freely into the air by such an installation.

, It will be understood that the cooled liquid which has been received in reservoir areas 68, 27 and 27 etc. is then free to flow away from the hot liquid channels to collecting cooled liquid channel 26 at the opposite end of the branch channels. From channel 26 the cooled liquid can either be recirculated to an installation which requires such liquid for cooling purposes and which then discharges heated liquid into the original channel 11, or channel 16 may be suitably connected to return the cooled liquid to a natural source, such as a river or lake from which it might have been drawn in the first place, used in a process which raises its temperature, and then fed into the heated liquid channel 11 for cooling by the installation of the present invention.

It will be understood that the spiral rotor units shown in the drawings represent a specific way of accomplishing the broader objectives of the installation and that other spraying devices can conceivably be used by those skilled in the art to provide a similar cooling effect, with a similar pattern, but with different individual spraying unit constructions.

*A modification of the liquid feeding means shown in FIG. 3 is illustrated in FIG. 4. Here the channel 16 again has its side wall 21 with an overflow edge 46 and a downhill liquid delivery surface 47. In this case the delivery surface terminates in an upwardly extending edge portion 71 so that its discharge edge 72 is spaced vertically above the lowermost portion 48 of the spillway. Thus the sheet of liquid which flows down the spillway is projected upwardly at an angle as shown by arrow 73 in a direction which has both a horizontal component 74 and an upward vertical component 76. In this'manner, the sheet of liquid not only moves horizontally into the path 'of the blades 78 of rotor 77, but the liquid is also movingupwardly in the same direction that rotor blades 78 are designed to move it, as rotor 77 rotates in a clockwise direction in FIG: 4 around its axis 79. Thus the blades can more effectively project the liquid drops in tangential trajectories as shown by arrow 81, so that groups of drops from each rotor blade will be projected upwardly and over into the cool liquid reservoir portion 27. 1

The liquid feeding means shown in FIGS. 2, 3 and 4 have the particular advantage that both the supply channels and the' liquid delivery surfaces are opentopped arrangements, so that there are no internal passageways which could be blocked by foreign materials in the supply of liquid. Any sticks or other objects which are carried along in the liquid can be removed from the upper surfaces of the liquid or of the feeding surface, and may even be projected out of the way by the rotating blade portions 78. With a one foot peripheral diameter rotor, and blade portions extending inwardly about 3 inches from the outer periphery, a vertical head of about 8 inches from overflow edge 46 to discharge edges 49 and 72 provides satisfactory operation at peripheral rotor speeds in the range of to 45 through a plurality ofopenings 83 in side wall 21. Man'- ifold 82 is further provided with a plurality of liquid:

projectingnozzles 84, each of which has internal liquid delivery surfaces 86 and discharge edges 87 to project individual sheets of liquid 93., (FIG. 6) into the path of blade portions of rotor 88. In this case the rotor blades 89 have a cross section, as viewed in FIG. 5, in a plane perpendicular to therotor axis, which includes a radially extending main blade portion 92 and an outer lip portion 91 inclined forwardly in the direction of rotation. Inclined lip portion 91, as rotor 88 rotates clockwise in FIG. 5, engages the liquid projected from nozzle edges 87 and assistsin drawing that liquid on to the main unperforated radial portion 92 of each rotor blade 89 for more efficient tangential projection of liquid upwardly and outwardly over receiving reservoir 27..As shown in FIG. 6, successive axially spaced cross sections of the individual rotor blades 89 are at relatively changing angular positions along the axis of the rotor shaft, so. that each blade is essentially helical, with an outer edge extending spirally along the rotor. This helical orientation not only projects the liquid at an angle to the rotor axis, as shown in FIG. 6, but has the further advantage of minimizing the noise of operation of such a rotor, as compared to a rotor in which axially in a straight axial blade-type of rotor, with either a continuous blade or with axially spaced blades (See FIG. 7 all the elementsof one blade throughout the length of the rotor axis will engage an incoming series of liquid sheets at the same angular position, with an intermittent slapping noise as successive blade portions each encounter the incoming liquid at the same moment. Either type of rotor can be used, however, in the installation of FIG. 6, and in either case the rotor shaft 94 will be supported in appropriate bearings 96 and driven by a power unit such as electric motor 97.

FIGS. 7 and 8 illustrate another arrangement of the liquid feeding means in which a liquid cooling assembly 101 includes a rotor member 102 having a shaft 103 supported for rotation on a horizontal axis. In this case ,the rotor includes axially spaced radially extending bladeportions 104 separated by axial spaces 106, with additional radial blade portions 107, 108, etc. spaced circumferentially around shaft 103 as shown in FIG. 8.

. In this case the liquid supply conduit 109 is a pressurized closed conduit located vertically below and parallel to the axis of shaft 103. A plurality of axially spaced nozzles 111 project upwardly from the conduit 109, and each nozzle has upwardly directed inner liquid delivery surfaces 112, terminating in discharge edges 1 13 immediately below the path of the rotor blade edges.

Sufficient pressure or head of liquid is maintained in connection with conduit 109, so that individual sheets of liquid will be projected upwardly into the angular spaces between successive blades 1 04, 107, etc. as the blades rotatepastthe nozzles.

. The arrangement of FIGS. 7 and 8 has the advantage that the rotor member. may be rotated in the direction of arrow 114 and thus project liquid drops generally to the. rightin 8 as shown by arrow 1 16, or the rotor :mernber c an be selectively rotated in the opposite direction as shown by arrow 117 to project liquid drops at the opposite side of the rotor as shown by arrow 1 18.

FIGS. 9, l and 11 show additional embodiments in which the liquid feeding means includes the combina* tion of an'open-topped liquid supply channel 121 defined by side walls 122 and 123 and bottom wall 124, with a rotor member 127 supported for rotation on a horizontal axis 128 at a level such that only the lowermost edge portions of the rotor'blades are arranged to project slightly below the surface level 126 of the liquid in supply channel 121. In this case the rotor member 127 includes spaced platesor discs 130 along the rotor shaft to support the ends of rotor blade sections 129. Each rotor blade portion 129, in this embodiment, includes a main liquid projecting portion 131 which has a cross section extending radially outwardly from axis 128 to an outer lip portion 132 which is inclined forwardly in the direction of rotation of the rotor to provide a part of the liquid feeding means. Thus the angular lip portion 132 serves as sort of a scoop or camming edge which picks up a thin sheet of liquid 133 from the upper surface 126 in the channel and urges the liquid 133 upwardly on to the main radial blade portion 131 for projection in the usual tangential trajectory as shown by arrow 134, when the rotor is moving in the direction shown by arrow 136. As shown more fully in FIG. 10, rotor shaft 137 is supported in bearings 138 and driven by a motor 139, supportedby cross members 141 and 142 which bridge limited axial areas between the side walls 122 and 123.

A furthermodification of the device of FIGS. 9 and is shown in FIG. 11, in which the rotor member 143 has axially extending blade portions 144, similar to the axially extending blades 129 in FIG. 10, except that blades 144 have two outer lip portions 148 and 149 which extend angularly in opposite directions around the circumference from'the main unperforated radial blade portions 147 of the rotor. When rotor 143 is rotated inthe direction of arrow' 136, the operation will be similar to that shown in' FIG. 9, in which lip portions 148 help lift some liquid from the surface in channel 121 up toward the main radial blade portions 147, so

thatsuch liquid can be projected tangentially in drops as shown by arrow 134. Conversely, when the rotor is turned in the opposite direction, as shown by arrow 151, the outer lip portions 149 will assist in feeding the liquid so that rotor blades 144 can project liquid drops in the opposite direction as shown by arrow 152.

In a typical rotor of the type shown in FIGS. 9 and 10, the rotor may have a diameter of one foot at the outer peripheral edges of the rotor blades, and each rotor blade may extend inwardly from its periphery for a radial distance of substantially 3 inches, with the outermost or peripheral lip portions extending at angles of substantially from the main radial portions of the blades, and with the length of each lip being approximately one inch of the, total three-inch radial distance of the entire blade 144. In the specific illustrations of FIGS. 9 11, the peripheral edge portions of the lips are permitted to dip below the surface 126'of liquid in channel 121 for a distance of only 1/32nd to'onequarter of an inch when the rotor is turned at an angular speed of substantially 600 rpm. (revolutions per minute). i I i In general, in the various embodiments described, the speed of rotation of the various rotor embodiments should be such that the peripheral speed at which the outermost blade edges move circumferentially will be in the range from 15 45 feet per second, so that liquid drops will be projected initially in tangential trajectories within this range of velocities to provide desirable drop sizes and effective volume rates of liquid projection. I

The foregoing specification sets forth some of the ways in which this invention may be practiced, including the best mode presently contemplated for carrying out the invention. Other modifications and variations may be apparent to those skilled in the art, in the light of the foregoing description and the following claims.

We claim:

1. A liquid cooling assembly comprising a liquidprojecting rotor member, and means supporting the rotor member for rotation on a generally horizontal axis, said rotor member having at least one paddle-like blade portion which has a cross section, as measured in a plane perpendicular to said axis, which extends generally radially outwardly from said axis and has an outer peripheral liquid-projecting edge, and liquid feeding means for feeding liquid inwardly from a location at the peripheral edge of the blade portion to the angular space swept by the blade portion during successive rotations of the rotor member around said axis, in which said liquid feeding means includes an opentopped liquid supply channel immediately below the rotor member for maintaining a supply of liquid with a surface level only slightly above the lowermost point swept during rotation of the outer peripheral liquidprojecting edge of the blade portion, said liquid feeding means also includes the outer peripheral liquidprojecting edge of the blade portion, in which said rotor member is rotatable selectively in opposite directions around said axis, and in which the outer peripheral liquid-projecting edge of the blade portion has short outer lip portions respectively extending in each opposite direction of rotation of the rotor member at an angle to the radially-extending blade portion, each outer lip portion projecting only slightly below the surface level of liquid to be maintained in said supply channel.

2. A large scale liquid cooling assembly for spraying heated liquid into the ambient atmospheric wind conditions above an open receiving reservoir for cooled liquid comprising a liquid-projecting rotor member, and means for supporting the rotor member for rotation on a generally horizontal axis adjacent such an open reservoir, said rotor member having at least one generally axially extending paddle-like blade portion which has a cross section, as measured in a plane perpendicular to said axis, which extends generally radially outwardly from said axis and has an outer peripheral liquid projecting edge, and liquid feeding means for feeding heated liquid inwardly from a location at the peripheral edge of the blade portion to the angular space swept by .the blade portion during successive rotations of the rotor member around said axis, in which said liquid feeding means includes a liquid supply conduit extending parallel to said axis close to the rotor member, and a liquid delivery device for feeding said liquid from the conduit to said angular space and in which the liquid supply conduit is a pressurized conduit below the rotor member, and the liquid delivery device includes upwardly directed nozzles having liquid delivery surfaces and discharge edges projecting liquid vertically upwardly from the pressurized conduit toward the rotor memberaxis and into said angular space.

3. A large scale liquid cooling assembly for spraying heated liquid into the ambient atmospheric wind conditions above an open receiving reservoir for cooled liq-' uid comprising a liquid-projecting rotor member, and means for supporting the rotor member for rotation on a generally horizontal axis adjacent such an open reservoir, said rotor member having at least one generally axially extending paddle-like blade portion which has a cross section, as measured in a plane perpendicular to said axis, which extends generally radially outwardly from said axis and has an outer peripheral liquidprojecting edge, and liquid feeding means for feeding heated liquid inwardly from a location at the peripheral edge of the blade portion to the angular spaceswept by the blade portion during successive rotations of the rotor member around said axis, in which said liquid feeding means includes a liquid supply conduit extending parallel to said axis close to the rotor member, and a liquid delivery device for feeding said liquid from the conduit to said angular space and in which the liquid supply conduit is an open-topped conduit having a sidewall extending along one side of the rotor member for maintaining a level of liquid higher than the vertical location of said rotor axis, said liquid delivery device inprojecting rotor member, and means supporting the rotor member for rotation on a generally horizontal axis, said rotor member having at least one paddle-like blade portion which has a cross section, as measured in a plane perpendicular to said axis, which extends generally radially outwardly from said axis and has an outer peripheral liquid-projecting edge, and liquid feeding means for feeding liquid inwardly from a location at the peripheral edge of the blade portion to the angular space swept by the blade portion during successive rotations of the rotor member around said axis, in which said liquid feeding means includes an opentopped liquid supply conduit extending parallel to said axis close to the rotor member and having a sidewall extending along one side of the rotor member for maintaining a level of liquid higher than the vertical location of said rotor axis, and a liquid delivery device for feeding said liquid from the conduit to said angular space, said liquid delivery device including a liquid delivery surface having a discharge edge at said one side of the rotor member immediately adjacent the-path swept by the outer peripheral edge of the rotor blade, and in which said liquid delivery device'include's an overflow edge along the top of the conduit side wall and said liquid delivery surface is a downwardly sloping opentopped liquid delivery surface extending downwardly and laterally toward said rotor member with its discharge edge extending parallel to the rotor axis fonprojecting a sheet of liquid into said angular space in a direction having a horizontal component of movement.

A liquid cooling assembly according to claim 5 in which the liquid delivery surface immediately adjacent saiddischarge edge extends upwardly for projecting said liquid into said angular space in a direction having a-horizontal component toward the rotor axis and an upward vertical component, said rotor being rotated around its axis in a direction moving its blade portion upwardly past said discharge edge.

- 7. A liquid cooling assembly according to claim 5 having means for rotating said rotor member on its horizontal axis at a peripheral speed, as measured circumferentially at its outer peripheral liquid-projecting edges, in the range from 15 to 45 feet per second, said rotor member having a plurality of equally angularly spaced radial blade portions, and said liquid feeding means having its overflow edge, delivery surface and delivery edge constructed and arranged for projecting said sheet of liquid inwardly at a linear speed insuring penetration of a substantial portion of such sheet inwardly at least A inch from the outer peripheral edges of each rotor blade portion toward the axis during the time interval defined by the movement of successive blade edges past the delivery surface edge.

8. A liquid cooling assembly according to claim 7 in which said rotor member has a diameter of substantially 1 foot, each blade portion extends radially inwardly from its outer peripheral edge {for a radial distance of substantially 3 inches, said discharge edge is substantially 8 inches lower than said overflow edge, and said rotor has four equally angularly spaced blade portions and has means rotating the rotor at an angular velocity of substantially 600 rpm. (revolutions per minute).

9. A large scale liquid cooling assembly for spraying heated liquid into the ambient atmospheric wind conditions above an open receiving reservoir for cooled liquid comprising a liquid-projecting rotor member, and means for supporting the rotor member for rotation on a generally horizontal axis adjacent such. an open reservoir, said rotor member having at least one generally axially extending paddle-like blade portion which has a cross section, as measured in a plane perpendicular to said axis, which extends generally radially outwardly from said axis and has an outer peripheral liquidprojecting edge, said blade portion having axially spaced cross sections at successively progressing relative radial angles, with such axially spaced cross sections defining an axially helically extending blade portion having an outer edge extending generally spirally around said axis, and liquid feeding means for feeding heated liquid inwardly from a location at the peripheral edge of the blade portion to the angular space swept by the blade portion during successive rotations of the rotor member around said axis, said liquid feeding means including an open-topped liquid supply channel immediately below the rotor member for maintaining a supply of liquid with a surface level only slightly above the lowermost point swept during rotation of the outer peripheral liquid-projecting edge of the blade portion.

1 0. A liquid cooling assembly according to claim 9 having a plurality of said blade portions spaced circumferentially around said axis.

l 1. A liquid cooling assembly according to claim 9 in which said liquid feeding means also includes the outer peripheral liquid-projecting edge of the blade portion,

said outer peripheral edge having a short outer lip portion extending forwardly in the direction of rotation of the rotor member at an angle to the radially-extending blade portion, with only said outer lip portion projecting slightly below the surface level of liquid to be maintained in said supply channel.

12. A liquid cooling assembly according to claim 9, in which said liquid feeding means includes the outer peripheral liquid-projecting edge of the blade portion, said outer peripheral edge having a short outer lip portion inclined forwardly in the direction of rotation of the rotor member at an angle to the radially-extending blade portion, said outer lip portion thereby assisting in drawing some liquid inwardly toward said axis onto said radially-extending blade portion for projection of liquid outwardly over said open receiving reservoir.

13. A liquid cooling assembly according to claim 9 having a plurality of individual axially extending blade portions spaced axially from each other along said axis.

14. A liquid cooling assembly according to claim 13 in which each axially spaced blade portion is positioned at a circumferential angle which locates said blade portion as a liquid-projecting surface which is substantially a continuation of the surface established by axially adjacent blade portions.

15. A liquid cooling assembly comprising a plurality of liquid cooling spray units arranged in generally parallel pairs of rows, with at least two such units in each row, the spray units in each such row of each pair being aligned and oriented to project liquid drops in trajectories which have horizontal components extending outwardly from such row and toward the opposite row of that pair, the spray units at the ends of each such row projecting such drops angularly in trajectories which have horizontal components extending angularly in a direction inclined toward the opposite ends of the opposite row of that pair, with the projected liquid drops providing wind effects drawing air inwardly from the ends of each pair of rows toward a central area between the opposite rows of such pair.

16. A liquid cooling assembly according to claim 15 having a plurality of liquid supply branch conduits extending generally parallel to each other and to said rows of spray units, with a supply branch conduit adjacent each row of spray units in each of said pairs, said assembly further including a main liquid supply conduit extending horizontally and generally perpendicular to said branch conduits along one end of said parallel rows, said main supply conduit supplying liquid to each of said branch conduits, and a liquid receiving reservoir having a portion extending generally perpendicular to said branch conduits along the opposite end of said parallel rows, said reservoir also including portions extending between the spray unit rows of each pair for receiving the liquid drops projected by said spray units into the central area between the opposite rows of each pair.

17. A liquid cooling assembly according to claim 16 in which said main and branch supply conduits include side wall portions providing open-topped channels, and in which the main supply conduit side wall has a limited liquid delivery opening communicating with each branch supply conduit for maintaining a higher liquid level in the main supply conduit than in the branch supply conduits, and valve means for closing each liquid delivery opening.

18. A liquid cooling assembly according to claim 16 in which each rotor member in said one row has a plurality of said blade portions spaced circumferentially around said axis, with each such blade portion having axially spaced cross sections at successively progressing relative radial angles, with such axially spaced cross sections defining an axially and helically extending blade portion having an outer edge extending generally spirally around said axis, the rotor members at opposite ends of said one row being rotated in the same direction around their axis of rotation and having respectively oppositely helically extending blade portions for projecting said liquid drops angularly in said trajectories which have horizontal components extending angularly in a direction inclined toward the opposite ends of the opposite row of spray units of the same pair.

19. A liquid cooling assembly according to claim 16 in which the spray units in at least one row comprise liquid projecting rotor members, and means supporting each rotor member for rotation on a generally horizontal axis parallel to said row, with each rotor member extending alongside a branch supply conduit, said rotor memberhaving at least one paddle-like blade portion which has a cross section, as measured in a plane perpendicular to said axis, which extends generally radially outwardly from said axis and has an outer peripheral liquid-projecting edge, liquid feeding means for feeding liquid inwardly from a location at the peripheral edge of the blade portion to the angular space swept by the blade portion during successive rotations of the rotor member around said axis, said liquid feeding means being connected to receive liquid from the branch supply conduit.

20. A liquid cooling assembly according to claim 19 in which the liquid feeding means includes a liquid delivery surface having a discharge edge parallel to said rotor axis and positioned at the side of said rotor member immediately adjacent the path swept by the outer v peripheral edge of the rotor blade.

21. A liquid cooling device according to claim 20 in which the main and branch supply conduits include side wall portions providing open-topped channels, and in which the liquid feeding means includes an overflow edge along the top of the branch supply conduit side wall, and said liquid delivery surface extending downwardly and laterally toward said rotor member with its discharge edge extending parallel to the rotor axis for projecting a sheet of liquid into said angular space in a direction having a horizontal component of movement. 

1. A liquid cooling assembly comprising a liquid-projecting rotor member, and means supporting the rotor member for rotation on a generally horizontal axis, said rotor member having at least one paddle-like blade portion which has a cross section, as measured in a plane perpendicular to said axis, which extends generally radially outwardly from said axis and has an outer peripheral liquid-projecting edge, and liquid feeding means for feeding liquid inwardly from a location at the peripheral edge of the blade portion to the angular space swept by the blade portion during successive rotations of the rotor member around said axis, in which said liquid feeding means includes an open-topped liquid supply channel immediately below the rotor member for maintaining a supply of liquid with a surface level only slightly above the lowermost point swept during rotation of the outer peripheral liquid-projecting edge of the blade portion, said liquid feeding means also includes the outer peripheral liquid-projecting edge of the blade portion, in which said rotor member is rotatable selectively in opposite directions around said axis, and in which the outer peripheral liquid-projecting edge of the blade portion has short outer lip poRtions respectively extending in each opposite direction of rotation of the rotor member at an angle to the radially-extending blade portion, each outer lip portion projecting only slightly below the surface level of liquid to be maintained in said supply channel.
 2. A large scale liquid cooling assembly for spraying heated liquid into the ambient atmospheric wind conditions above an open receiving reservoir for cooled liquid comprising a liquid-projecting rotor member, and means for supporting the rotor member for rotation on a generally horizontal axis adjacent such an open reservoir, said rotor member having at least one generally axially extending paddle-like blade portion which has a cross section, as measured in a plane perpendicular to said axis, which extends generally radially outwardly from said axis and has an outer peripheral liquid-projecting edge, and liquid feeding means for feeding heated liquid inwardly from a location at the peripheral edge of the blade portion to the angular space swept by the blade portion during successive rotations of the rotor member around said axis, in which said liquid feeding means includes a liquid supply conduit extending parallel to said axis close to the rotor member, and a liquid delivery device for feeding said liquid from the conduit to said angular space and in which the liquid supply conduit is a pressurized conduit below the rotor member, and the liquid delivery device includes upwardly directed nozzles having liquid delivery surfaces and discharge edges projecting liquid vertically upwardly from the pressurized conduit toward the rotor member axis and into said angular space.
 3. A large scale liquid cooling assembly for spraying heated liquid into the ambient atmospheric wind conditions above an open receiving reservoir for cooled liquid comprising a liquid-projecting rotor member, and means for supporting the rotor member for rotation on a generally horizontal axis adjacent such an open reservoir, said rotor member having at least one generally axially extending paddle-like blade portion which has a cross section, as measured in a plane perpendicular to said axis, which extends generally radially outwardly from said axis and has an outer peripheral liquid-projecting edge, and liquid feeding means for feeding heated liquid inwardly from a location at the peripheral edge of the blade portion to the angular space swept by the blade portion during successive rotations of the rotor member around said axis, in which said liquid feeding means includes a liquid supply conduit extending parallel to said axis close to the rotor member, and a liquid delivery device for feeding said liquid from the conduit to said angular space and in which the liquid supply conduit is an open-topped conduit having a sidewall extending along one side of the rotor member for maintaining a level of liquid higher than the vertical location of said rotor axis, said liquid delivery device including a liquid delivery surface having a discharge edge at said one side of the rotor member immediately adjacent the path swept by the outer peripheral edge of the rotor blade.
 4. A liquid cooling assembly according to claim 3 in which said liquid delivery device includes a manifold on said outer wall having a plurality of horizontally and axially spaced nozzles each providing individual liquid delivery surfaces and discharge edges across which liquid is projected with a horizontal component of movement into said angular space.
 5. A liquid cooling assembly comprising a liquid-projecting rotor member, and means supporting the rotor member for rotation on a generally horizontal axis, said rotor member having at least one paddle-like blade portion which has a cross section, as measured in a plane perpendicular to said axis, which extends generally radially outwardly from said axis and has an outer peripheral liquid-projecting edge, and liquid feeding means for feeding liquid inwardly from a location at the peripheral edge of the blade portion to the angulAr space swept by the blade portion during successive rotations of the rotor member around said axis, in which said liquid feeding means includes an open-topped liquid supply conduit extending parallel to said axis close to the rotor member and having a sidewall extending along one side of the rotor member for maintaining a level of liquid higher than the vertical location of said rotor axis, and a liquid delivery device for feeding said liquid from the conduit to said angular space, said liquid delivery device including a liquid delivery surface having a discharge edge at said one side of the rotor member immediately adjacent the path swept by the outer peripheral edge of the rotor blade, and in which said liquid delivery device includes an overflow edge along the top of the conduit side wall and said liquid delivery surface is a downwardly sloping open-topped liquid delivery surface extending downwardly and laterally toward said rotor member with its discharge edge extending parallel to the rotor axis for projecting a sheet of liquid into said angular space in a direction having a horizontal component of movement.
 6. A liquid cooling assembly according to claim 5 in which the liquid delivery surface immediately adjacent said discharge edge extends upwardly for projecting said liquid into said angular space in a direction having a horizontal component toward the rotor axis and an upward vertical component, said rotor being rotated around its axis in a direction moving its blade portion upwardly past said discharge edge.
 7. A liquid cooling assembly according to claim 5 having means for rotating said rotor member on its horizontal axis at a peripheral speed, as measured circumferentially at its outer peripheral liquid-projecting edges, in the range from 15 to 45 feet per second, said rotor member having a plurality of equally angularly spaced radial blade portions, and said liquid feeding means having its overflow edge, delivery surface and delivery edge constructed and arranged for projecting said sheet of liquid inwardly at a linear speed insuring penetration of a substantial portion of such sheet inwardly at least 1/4 inch from the outer peripheral edges of each rotor blade portion toward the axis during the time interval defined by the movement of successive blade edges past the delivery surface edge.
 8. A liquid cooling assembly according to claim 7 in which said rotor member has a diameter of substantially 1 foot, each blade portion extends radially inwardly from its outer peripheral edge for a radial distance of substantially 3 inches, said discharge edge is substantially 8 inches lower than said overflow edge, and said rotor has four equally angularly spaced blade portions and has means rotating the rotor at an angular velocity of substantially 600 r.p.m. (revolutions per minute).
 9. A LARGE SCALE LIQUID COOLING ASSEMBLY FOR SPRAYING HEATED LIQUID INTO THE AMBIENT ATMOSPHERIC WIND CONDITIONS ABOVE AN OPEN RECEIVING RESERVOIR FOR COOLED LIQUID COMPRISING A LIQUIDPROJECTING ROTOR MEMBER, AND MEANS FOR SUPPORTING THE ROTOR MEMBER FOR ROTATION ON A GENERALLY HORIZONTAL AXIS ADJACENT SUCH AN OPEN RESERVOIR, SAID ROTOR MAMBER HAVING AT LEAST ONE GENERALLY AXIALLY EXTENDING PADDLE-LIKE BLADE PORTION WHICH HAS A CROSS SECTION, AS MEASURED IN A PLANE PERPENDICULAR TO SAID AXIS, WHICH EXTENDS GENERALLY RADIALLY OUTWARDLY FROM SAID AXIS AND HAS AN OUTER PERIPHERAL LIQUID-PROJECTING EDGE, SAID BLADE PORTION HAVING AXIALLY SPACED CROSS SECTIONS AT SUCCESSIVELY PROGRESSING RELATIVE RADIAL ANGLES, WITH SUCH AXIALLY SPACED CROSS SECTIONS DEFINING AN AXIALLY HELICALLY EXTENDING BLADE PORTION HAVING AN OUTER EDGE EXTENDING GENERALLY SPIRALLY AROUN SAID AXIS, AND LIQUID FEEDING MEANS FOR FEEDING HEATED LIQUID INWARDLY FROM A LOCATION AT THE PERIPHERAL EDGE OF THE BLADE PORTION TO THE ANGULAR SPACE SWEPT BY THE BLADE PORTION DURING SUCCESSIVE ROTATIONS OF THE ROTOR MEMBERBLADE AROUND SAID AXIS, SAID LIQUID FEEDING MEANS INCLUDING AN OPENTOPPED LIQUID SUPPLY CHANNEL IMMEDIATELY BELOW THE THE ROTOR MEMBER FOR MAINTAINING A SUPPLY OF LIQUID WITH A SURFACE LEVEL ONLY SLIGHTLY ABOVE THE LOWERMOST POINT SWEPT DURING ROTATION OF THE OUTER PERIPHERAL LIQUID-PROJECTING EDGE OF THE BLADE PORTION.
 10. A liquid cooling assembly according to claim 9 having a plurality of said blade portions spaced circumferentially around said axis.
 11. A liquid cooling assembly according to claim 9 in which said liquid feeding means also includes the outer peripheral liquid-projecting edge of the blade portion, said outer peripheral edge having a short outer lip portion extending forwardly in the direction of rotation of the rotor member at an angle to the radially-extending blade portion, with only said outer lip portion projecting slightly below the surface level of liquid to be maintained in said supply channel.
 12. A liquid cooling assembly according to claim 9, in which said liquid feeding means includes the outer peripheral liquid-projecting edge of the blade portion, said outer peripheral edge having a short outer lip portion inclined forwardly in the direction of rotation of the rotor member at an angle to the radially-extending blade portion, said outer lip portion thereby assisting in drawing some liquid inwardly toward said axis onto said radially-extending blade portion for projection of liquid outwardly over said open receiving reservoir.
 13. A liquid cooling assembly according to claim 9 having a plurality of individual axially extending blade portions spaced axially from each other along said axis.
 14. A liquid cooling assembly according to claim 13 in which each axially spaced blade portion is positioned at a circumferential angle which locates said blade portion as a liquid-projecting surface which is substantially a continuation of the surface established by axially adjacent blade portions.
 15. A LIQUID COOLING ASSEMBLY COMPRISING A PLURALITY OF LIQUID COOLING SPRAY UNITS ARRANGED IN GENERALLY PARALLEL PAIRS OF ROWS, WITH AT LEAST TWO SUCH UNITS IN EACH ROW THE SPRAY UNITS IN EACH SUCH ROW OF EACH PAIR BEING ALIGNED AND ORIENTED TO PROJECT LIQUID DROPS IN TRAJECTORIES WHICH HAVE HORIZONTAL COMPONENTS EXTENDING OUTWARDLY FROM SUCH ROW AND TOWARD THE OPPOSITE ROW OF THAT PAIR, THE SPRAY UNITS AT THE ENDS OF EACH SUCH ROW PROJECTING SUCH DROPS ANGULARLY IN TRAJECTORIES WHICH HAVE HORIZONTAL COMPONENTS EXTENDING ANGULARLY IN A DIRECTION INCLINED TOWARD THE OPPOSITE ENDS OF THE OPPOSITE ROW OF THAT PAIR, WITH THE PROJECTED LIQUID DROPS PROVIDING WIND EFFECTS DRAWING AIR INWARDLY FROM THE ENDS OF EACH PAIR OF ROWS TOWARD A CENTRAL AREA BETWEEN THE OPPOSITE ROWS OF SUCH PAIR.
 16. A liquid cooling assembly according to claim 15 having a plurality of liquid supply branch conduits extending generally parallel to each other and to said rows of spray units, with a supply branch conduit adjacent each row of spray units in each of said pairs, said assembly further including a main liquid supply conduit extending horizontally and generally perpendicular to said branch conduits along one end of said parallel rows, said main supply conduit supplying liquid to each of said branch conduits, and a liquid receiving reservoir having a portion extending generally perpendicular to said branch conduits along the opposite end of said parallel rows, said reservoir also including portions extending between the spray unit rows of each pair for receiving the liquid drops projected by said spray units into the central area between the opposite rows of each pair.
 17. A liquid cooling assembly according to claim 16 in which said main and branch supply conduits include side wall portions providing open-topped channels, and in which the main supply conduit side wall has a limited liquid delivery opening communicating with each branch supply conduit for maintaining a higher liquid level in the main supply conduit than in the branch supply conduits, and valve means for closing each liquid delivery opening.
 18. A liquid coolIng assembly according to claim 16 in which each rotor member in said one row has a plurality of said blade portions spaced circumferentially around said axis, with each such blade portion having axially spaced cross sections at successively progressing relative radial angles, with such axially spaced cross sections defining an axially and helically extending blade portion having an outer edge extending generally spirally around said axis, the rotor members at opposite ends of said one row being rotated in the same direction around their axis of rotation and having respectively oppositely helically extending blade portions for projecting said liquid drops angularly in said trajectories which have horizontal components extending angularly in a direction inclined toward the opposite ends of the opposite row of spray units of the same pair.
 19. A liquid cooling assembly according to claim 16 in which the spray units in at least one row comprise liquid projecting rotor members, and means supporting each rotor member for rotation on a generally horizontal axis parallel to said row, with each rotor member extending alongside a branch supply conduit, said rotor member having at least one paddle-like blade portion which has a cross section, as measured in a plane perpendicular to said axis, which extends generally radially outwardly from said axis and has an outer peripheral liquid-projecting edge, liquid feeding means for feeding liquid inwardly from a location at the peripheral edge of the blade portion to the angular space swept by the blade portion during successive rotations of the rotor member around said axis, said liquid feeding means being connected to receive liquid from the branch supply conduit.
 20. A liquid cooling assembly according to claim 19 in which the liquid feeding means includes a liquid delivery surface having a discharge edge parallel to said rotor axis and positioned at the side of said rotor member immediately adjacent the path swept by the outer peripheral edge of the rotor blade.
 21. A liquid cooling device according to claim 20 in which the main and branch supply conduits include side wall portions providing open-topped channels, and in which the liquid feeding means includes an overflow edge along the top of the branch supply conduit side wall, and said liquid delivery surface extending downwardly and laterally toward said rotor member with its discharge edge extending parallel to the rotor axis for projecting a sheet of liquid into said angular space in a direction having a horizontal component of movement. 